Polymer resin manufacturing process

Note that the material of this example corresponds to the Polymer Resin example of SchedulePro. Its ReadMe file includes the figures of this example in color and it is available online [146]. A functional evaluation version of SchedulePro is available online as well [147]. 

The relative timing of the various operations is determined by the operation s duration and by scheduling relationships among operations. An operation s duration may be fixed, rate-based (i.e., dependent on the amount of material processed), inventory-dependent (i.e., related to the time it takes for a storage unit to reach a specified level), or specified to be equivalent to the duration of another operation. Each operation s timing may be set relative to the start of a batch or the start or end time of another operation. Flexible shifts related to operation start times can also be specified, in order to allow an operation to be delayed automatically if some of its required resources are not available at its scheduled start time [148]. 

SchedulePro provides a number of other recipe views for easy editing of labor, auxiliary equipment, materials, and other resources. 

If a batch process is already modeled in SuperPro Designer, its recipe can be exported to SchedulePro via a recipe database. The same is possible with batch process automation and manufacturing execution systems that foUow the ISA S-88 standards for batch recipe representation. Alternatively, recipes can be created by users directly in SchedulePro. 

The next two lines represent the occupancy of the two wash vessels (WV-1 and 

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Dicyclopentadiene is also polymerized with tungsten-based catalysts. Because the polymerization reaction produces heavily cross-Unked resins, the polymers are manufactured in a reaction injection mol ding (RIM) process, in which all catalyst components and resin modifiers are slurried in two batches of the monomer. The first batch contains the catalyst (a mixture of WCl and WOCl, nonylphenol, acetylacetone, additives, and fillers the second batch contains the co-catalyst (a combination of an alkyl aluminum compound and a Lewis base such as ether), antioxidants, and elastomeric fillers (qv) for better moldabihty (50). Mixing two Uquids in a mold results in a rapid polymerization reaction. Its rate is controlled by the ratio between the co-catalyst and the Lewis base. Depending on the catalyst composition, solidification time of the reaction mixture can vary from two seconds to an hour. Similar catalyst systems are used for polymerization of norbomene and for norbomene copolymerization with ethyhdenenorbomene. 

Some of the common types of plastics that ate used ate thermoplastics, such as poly(phenylene sulfide) (PPS) (see Polymers containing sulfur), nylons, Hquid crystal polymer (LCP), the polyesters (qv) such as polyesters that ate 30% glass-fiber reinforced, and poly(ethylene terephthalate) (PET), and polyetherimide (PEI) and thermosets such as diaHyl phthalate and phenoHc resins (qv). Because of the wide variety of manufacturing processes and usage requirements, these materials ate available in several variations which have a range of physical properties. 

The type of manufacturing process, reaction conditions, and catalyst are the controlling factors for the molecular structure of the polymers [4-8]. The molecular features govern the melt processability and microstructure of the solids. The formation of the microstructure is also affected by the melt-processing conditions set for shaping the polymeric resin [9]. The ultimate properties are, thus, directly related to the microstructural features of the polymeric solid. 

Residual catalyst (expressed as ash content). The actual residues depend on the manufacturing process used and on the characteristics of the polymer. The so-called new generation HD-PE processes such as the Solvay process use superactive catalysts which produce polymers with a low ash content and, hence, low or negligible odor. Some narrow MWD (Molecular Weight Distribution) resins also have lower catalyst residues than their wide MWD counterparts. 

Most of the benzene used in chemical applications ends up in the manufacturing processes for styrene (covered in Chapter 8), cumene (covered in Chapter 7), and cyclohexane (covered in Chapter 4), Polymers and all sorts of plastics are produced from styrene. Cumene is the precursor to phenol, which ultimately ends up in resins and adhesives, mostly for gluing plywood together. The production of styrene and phenol account for. about 70% of the benzene produced. Cyclohexane, used to make Nylon 6 and Nylon 66, is the next biggest application of benzene. 

The formaldehyde process is an air oxidation of methanol, CH3OH, which has water as a by-product. Formaldehyde is a gas at room temperature, but is usually handled either as a water solution called formalin or as polymers called paraformaldehyde and trioxane. Both are readily converted back ro formaldehyde. Some uses of formaldehyde are the manufacture of polymer resins and as a germicide. 

Shaw selected a combination of polyolefin resins as the base polymer of choice for its substitute, EcoWorx . Due to the low toxicity of its feedstocks, superior adhesion properties, dimensional stability, and its ability to be recycled, EcoWorx meets all of the design criteria necessary to satisfy the needs of the marketplace from a performance, health, and environmental standpoint. Research also indicated that the post-consumer carpet tile had a positive economic value at the end of its useful life. The cost of collection, transportation, elutriation, and return to manufacturing processes is less than the cost of using virgin raw materials. This is a truly recyclable (or Cradle to Cradle) product and is a good example of how substitution through innovation can make economic as well as environmental sense. ... 

The polymerization of phenols or aromatic amines is applied in resin manufacture and the removal of phenols from waste water. Polymers produced by HRP-catalyzed coupling of phenols in non-aqueous media are potential substitutes for phenol-formaldehyde resins [123,124], and the polymerized aromatic amines find applications as conductive polymers [112]. Phenols and their resins are pollutants in aqueous effluents derived from coal conversion, paper-making, production of semiconductor chips, and the manufacture of resins and plastics. Their transformation by peroxidase and hydrogen peroxide constitutes a convenient, mild and environmentally acceptable detoxification process [125-127]. 

Dermal/Ocular Effects. No skin lesions or dermatitis were reported in an early review of the dermatological problems associated with the manufacture of coumarone-indene resin (a polymer made from 2,3-benzofuran and indene) however, the manufacturing process essentially prevented contact with monomers (Schwartz 1936), so the significance of these negative findings is questionable. Workers continuously exposed to wood varnished with coumarone-indene resin developed dermatitis, but the sensitivity was attributed to the sulfuric acids in the varnish (Schwartz 1936). 

The first successful static firing of plastisol propellant took place late in 1950 as part of a broad program conducted by Atlantic Research Corp. to investigate and evaluate plastisol propellants and methods for their manufacture (16). Major attention was directed to poly (vinyl chloride), cellulose acetate, and nitrocellulose, although other polymers were tested for their suitability (17). Patent applications were filed for plastisol propellant compositions and manufacturing processes, based on poly(vinyl chloride) (PVC) (19) and on nitrocellulose (18). The commercial availability of dispersion grade PVC enabled work with this resin to advance rapidly. The balance of this paper is devoted to a discussion of PVC plastisol propellants and their manufacture. 

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